The proposed study intends to continue studying the electrical properties of the mitochondrial membrane using microelectrodes. In particular, the study will examine the factors affecting the membrane resistance of mitochondria including such parameters as (a) the presence and absence of valinomycin, (b) the ionic composition of the medium, (c) the metabolic state of the mitochondria and (d) the magnitude of the current used to measure the resistance. In addition, we will attempt to examine the possibility of whether ATP can be produced by the mitochondrial membrane when current is passed between an internal and an external microelectrode.